Aluminum iron based alloys can have mechanical properties comparable to some titanium alloys at elevated temperatures, such as temperatures of about 350 degrees centigrade (° C.). In particular, rapidly solidified (RS) aluminum iron based alloys have desirable properties. The RS aluminum iron based alloys are lighter than the titanium alloys, so they can provide comparable performance with less weight. However, the fabrication process for the aluminum iron based alloys is complex, and this has limited commercial use and exploitation of the beneficial properties.
The microstructure of aluminum iron based alloys impacts the properties of the alloy, and the microstructure depends on the manufacturing process. The microstructure can include dispersoids that are important to the properties of RS aluminum iron based alloys, and these dispersoids are undesirably coarsened if the alloys are processed at temperatures above about 500° C. or 550° C. The coarsening reduces the alloy strength and creep resistance. The coarsened dispersoids can be solutionized in the solid state, but they can't be re-precipitated in the form of very fine sized particles that are desirable, without re-melting and beginning the rapid solidification process again. Furthermore, processing at temperatures approaching or above about 500° C. can result in the precipitation of equilibrium intermetallic compounds leading to alloy embrittlement.
RS aluminum iron based alloys have been formed by melting, followed by rapid solidification and particulates formation, degassing, and finally by compaction. Absorbed water, hydrates, and/or hydroxides are present in the solidified particulates, and these water species, hydrates, or hydroxides gradually produce aluminum oxide so higher moisture, hydrate, or hydroxide concentrations increase the aluminum oxide concentration in the comminuted ribbon, flake, or powder particulates. Aluminum oxide in the form of film or stringers decreases the ductility and toughness, and also increases the brittleness of the final product. Aluminum oxide also undesirably increases the directionality of properties if the alloy is extruded.
Accordingly, it is desirable to provide aluminum iron based alloys and methods of producing the same with reduced moisture contents, lower concentrations of hydrates and/or hydroxides, and therefore lower concentrations of aluminum oxide. In addition, it is desirable to provide aluminum iron based alloys and methods of producing the same with higher ductility, lower brittleness, and lower directionality of properties than in traditional aluminum iron based alloys. Furthermore, other desirable features and characteristics of the present embodiment will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.